1/**********
2This library is free software; you can redistribute it and/or modify it under
3the terms of the GNU Lesser General Public License as published by the
4Free Software Foundation; either version 3 of the License, or (at your
5option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)
6
7This library is distributed in the hope that it will be useful, but WITHOUT
8ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
9FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
10more details.
11
12You should have received a copy of the GNU Lesser General Public License
13along with this library; if not, write to the Free Software Foundation, Inc.,
1451 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
15**********/
16// "liveMedia"
17// Copyright (c) 1996-2020 Live Networks, Inc. All rights reserved.
18// MP3 File Sources
19// Implementation
20
21#include "MP3FileSource.hh"
22#include "MP3StreamState.hh"
23#include "InputFile.hh"
24
25////////// MP3FileSource //////////
26
27MP3FileSource::MP3FileSource(UsageEnvironment& env, FILE* fid)
28 : FramedFileSource(env, fid),
29 fStreamState(new MP3StreamState(env)) {
30}
31
32MP3FileSource::~MP3FileSource() {
33 delete fStreamState;
34}
35
36char const* MP3FileSource::MIMEtype() const {
37 return "audio/MPEG";
38}
39
40MP3FileSource* MP3FileSource::createNew(UsageEnvironment& env, char const* fileName) {
41 MP3FileSource* newSource = NULL;
42
43 do {
44 FILE* fid;
45
46 fid = OpenInputFile(env, fileName);
47 if (fid == NULL) break;
48
49 newSource = new MP3FileSource(env, fid);
50 if (newSource == NULL) break;
51
52 unsigned fileSize = (unsigned)GetFileSize(fileName, fid);
53 newSource->assignStream(fid, fileSize);
54 if (!newSource->initializeStream()) break;
55
56 return newSource;
57 } while (0);
58
59 Medium::close(newSource);
60 return NULL;
61}
62
63float MP3FileSource::filePlayTime() const {
64 return fStreamState->filePlayTime();
65}
66
67unsigned MP3FileSource::fileSize() const {
68 return fStreamState->fileSize();
69}
70
71void MP3FileSource::setPresentationTimeScale(unsigned scale) {
72 fStreamState->setPresentationTimeScale(scale);
73}
74
75void MP3FileSource::seekWithinFile(double seekNPT, double streamDuration) {
76 float fileDuration = filePlayTime();
77
78 // First, make sure that 0.0 <= seekNPT <= seekNPT + streamDuration <= fileDuration
79 if (seekNPT < 0.0) {
80 seekNPT = 0.0;
81 } else if (seekNPT > fileDuration) {
82 seekNPT = fileDuration;
83 }
84 if (streamDuration < 0.0) {
85 streamDuration = 0.0;
86 } else if (seekNPT + streamDuration > fileDuration) {
87 streamDuration = fileDuration - seekNPT;
88 }
89
90 float seekFraction = (float)seekNPT/fileDuration;
91 unsigned seekByteNumber = fStreamState->getByteNumberFromPositionFraction(seekFraction);
92 fStreamState->seekWithinFile(seekByteNumber);
93
94 fLimitNumBytesToStream = False; // by default
95 if (streamDuration > 0.0) {
96 float endFraction = (float)(seekNPT + streamDuration)/fileDuration;
97 unsigned endByteNumber = fStreamState->getByteNumberFromPositionFraction(endFraction);
98 if (endByteNumber > seekByteNumber) { // sanity check
99 fNumBytesToStream = endByteNumber - seekByteNumber;
100 fLimitNumBytesToStream = True;
101 }
102 }
103}
104
105void MP3FileSource::getAttributes() const {
106 char buffer[200];
107 fStreamState->getAttributes(buffer, sizeof buffer);
108 envir().setResultMsg(buffer);
109}
110
111void MP3FileSource::doGetNextFrame() {
112 if (!doGetNextFrame1()) {
113 handleClosure();
114 return;
115 }
116
117 // Switch to another task:
118#if defined(__WIN32__) || defined(_WIN32)
119 // HACK: liveCaster/lc uses an implementation of scheduleDelayedTask()
120 // that performs very badly (chewing up lots of CPU time, apparently polling)
121 // on Windows. Until this is fixed, we just call our "afterGetting()"
122 // function directly. This avoids infinite recursion, as long as our sink
123 // is discontinuous, which is the case for the RTP sink that liveCaster/lc
124 // uses. #####
125 afterGetting(this);
126#else
127 nextTask() = envir().taskScheduler().scheduleDelayedTask(0,
128 (TaskFunc*)afterGetting, this);
129#endif
130}
131
132Boolean MP3FileSource::doGetNextFrame1() {
133 if (fLimitNumBytesToStream && fNumBytesToStream == 0) return False; // we've already streamed as much as we were asked for
134
135 if (!fHaveJustInitialized) {
136 if (fStreamState->findNextHeader(fPresentationTime) == 0) return False;
137 } else {
138 fPresentationTime = fFirstFramePresentationTime;
139 fHaveJustInitialized = False;
140 }
141
142 if (!fStreamState->readFrame(fTo, fMaxSize, fFrameSize, fDurationInMicroseconds)) {
143 char tmp[200];
144 sprintf(tmp,
145 "Insufficient buffer size %d for reading MPEG audio frame (needed %d)\n",
146 fMaxSize, fFrameSize);
147 envir().setResultMsg(tmp);
148 fFrameSize = fMaxSize;
149 return False;
150 }
151 if (fNumBytesToStream > fFrameSize) fNumBytesToStream -= fFrameSize; else fNumBytesToStream = 0;
152
153 return True;
154}
155
156void MP3FileSource::assignStream(FILE* fid, unsigned fileSize) {
157 fStreamState->assignStream(fid, fileSize);
158}
159
160
161Boolean MP3FileSource::initializeStream() {
162 // Make sure the file has an appropriate header near the start:
163 if (fStreamState->findNextHeader(fFirstFramePresentationTime) == 0) {
164 envir().setResultMsg("not an MPEG audio file");
165 return False;
166 }
167
168 fStreamState->checkForXingHeader(); // in case this is a VBR file
169
170 fHaveJustInitialized = True;
171 fLimitNumBytesToStream = False;
172 fNumBytesToStream = 0;
173
174 // Hack: It's possible that our environment's 'result message' has been
175 // reset within this function, so set it again to our name now:
176 envir().setResultMsg(name());
177 return True;
178}
179